The present invention relates to a leg mechanism.
The purpose of a load-carrying leg mechanism is described particularly in the U.S. Pat. No. 5,353,886 of the same applicant. The purpose of the leg mechanisms of this kind is on one hand to support a load caused by the body of the device which they are carrying and on the other hand to accomplish advancing movement. Such leg mechanisms having an upper arm and a lower arm are commonly used in conjunction with so-called "walking machines". The model for the movements of such machines is obtained from the legs of mammals where the walking movement causing the advancement is dependent on movement paths of the thigh (upper arm) joined to the body (frame) through the hip joint and the shin (lower arm) joined thereto through the knee joint. These paths are created as a result of pivotal movements taking place with respect to the joints.
When the movement paths of the nature are imitated by machines, high demands are set on actuators moving the above-mentioned parts and on the control operations related thereto. In order to have correct movements of the leg mechanism in view of the movement paths and load situations at every moment, the control and steering systems must be highly sophisticated and functionally reliable to permit the advancing movement and the supporting of the load without any disturbances.